"The last few years, as well as the many years before, Matt controlled all of the women on the show and had all the men bowing and scraping to him."

A former Today staffer added, "For Matt, some women on the show were just a one-time thing, and he never spoke to them again. Other women he had affairs with. And others he just picked up and disposed of when he felt like it.

"The most horrible thing was that he made it clear that if they ever spoke out or crossed him, they would be fired from the show, negative stories leaked about them, and their careers would be destroyed," the source said.

"So it is insulting to see the pretend shock on the faces of the people at Today after Lauer was fired. This is just theatrics."

The list of who knew about Lauer's behaviour before the scandal exploded on Tuesday started at the top, sources said.

Current NBC News President Noah Oppenheim and chairman Andy Lack "knew of the investigations into Matt's behaviour and tried to negotiate."

Capus, who was president of NBC News from 2005 to 2013, and Jim Bell, the executive producer of Today until December 2012, were mostly concerned about keeping Lauer happy, according to sources.

So was the anchorman's personal producer, Don Nash, who is now executive producer of the morning program, sources said.

"The show was a total boys' club, even despite it having a very large female staff," one source said.

Bell, who went on to produce NBC's Olympic coverage, even "enabled" Lauer's bad behaviour, including his affairs with staffers and show contributors, another NBC executive alleged.

"There was a boys' club mentality in the control room and in the hallways, and any complaints about that were dismissed," the source said.

"It was always made out that these affairs were consensual, a joke about how many women had slept with Matt or had affairs with him. It was never suggested that the women were victims."

Later was swiftly fired after an NBC employee came forward to company officials accusing the longtime TV host of sexual harassment.

Within hours, two more women filed complaints with the media company, including one former employee who said Lauer sexually assaulted her in his office after locking the door.

Lauer allegedly had a button on his desk to remotely lock his office door, including one time in which he is accused of having sex with a co-worker bent over his desk. He also allegedly flashed his penis to at least one colleague and invited co-workers to his hotel room at odd hours while travelling, accusers told Variety in a bombshell exposé Wednesday.